[LINK] "The Carrington Flare"

[rfmcdonald]

Over at Passing Strangeness, pauldrye has a post up describing the background of the Carrington Flare, a massive solar eruption in 1859 that occurred just as Victorian science was beginning to understand the true nature of the universe.

The connections between light, magnetism, and electricity were still incompletely understood in 1859 (James Clerk Maxwell would not entirely coincidentally publish his tour de force on the subject over the next few years), but Michael Faraday had already discovered the Law of Induction. Shorn of mathematics, it provided for the creation of electricity if a piece of metal cuts across a magnetic field or the field instead cuts over the metal. That was the connection between the strange readings at Kew and the telegraphic events around the world. The enormous auroras were symptomatic of huge fluctuations in the Earth’s magnetic field, and those fluctuations were playing across the world’s 200,000 kilometers of telegraph wire. By analyzing the directions followed by wires and comparing them to the effects that occurred at their stations, it was even possible to develop a rough idea of how the fluctuations had flowed around the planet.

If anything like that event happened now, Paul points out, the consequences would be dire.

Nothing like 1859’s storm has happened again, not at the same intensity anyway. There were smaller, but still extensive storms in May 1921, 1960, and March 1989. By 1989 there were no more telegraphs, but there were electrical power lines; that last storm’s induced currents knocked out power over much of Québec by damaging transformers and electrical equipment. If something like 1859’s event were to occur today, we’d probably end up with a similar power failure across large swathes of the Northern Hemisphere, and be in the dark for a few days until enough pieces could be salvaged from the non-functional plant for use in what can be saved. Based on studies of ice cores, astronomers estimate that we only get something that size on average every 500 years or so, but it’s bit like a big earthquake—”on average” could just as easily come up tomorrow.